////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2019-2021 The Octave Project Developers
//
// See the file COPYRIGHT.md in the top-level directory of this
// distribution or <https://octave.org/copyright/>.
//
// This file is part of Octave.
//
// Octave is free software: you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Octave is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Octave; see the file COPYING.  If not, see
// <https://www.gnu.org/licenses/>.
//
////////////////////////////////////////////////////////////////////////

#if defined (HAVE_CONFIG_H)
#  include "config.h"
#endif

#include <algorithm>
#include <string>

#include <QFileIconProvider>
#include <QMessageBox>
#include <QtAlgorithms>

#include "qt-interpreter-events.h"
#include "set-path-model.h"

#include "pathsearch.h"

#include "interpreter.h"
#include "load-path.h"

namespace octave
{
  set_path_model::set_path_model (QObject *p)
    : QAbstractListModel (p)
  {
    connect (this, &set_path_model::update_data_signal,
             this, &set_path_model::update_data);

    m_revertible = false;
  }

  std::string set_path_model::to_string (void)
  {
    std::string path_sep = directory_path::path_sep_str ();

    std::string path_str;

    QStringList::iterator it = m_dirs.begin ();

    while (it < m_dirs.end ())
      {
        if (it != m_dirs.begin ())
          path_str += path_sep;
        path_str += it->toStdString ();
        ++it;
      }

    return path_str;
  }

  void set_path_model::model_to_path (void)
  {
    std::string path_str = to_string ();

    emit interpreter_event
      ([=] (interpreter& interp)
       {
         // INTERPRETER THREAD

         load_path& lp = interp.get_load_path ();

         lp.set (path_str);
       });
  }

  void set_path_model::clear (void)
  {
    beginResetModel ();

    m_dirs.clear ();

    endResetModel ();
  }

  void set_path_model::save (void)
  {
    model_to_path ();

    emit interpreter_event
      ([] (interpreter& interp)
       {
         // INTERPRETER THREAD

         interp.feval ("savepath");
       });
  }

  void set_path_model::revert (void)
  {
    clear ();

    beginInsertRows (QModelIndex (), 0, m_orig_dirs.size () - 1);
    m_dirs = m_orig_dirs;
    endInsertRows ();

    model_to_path ();
  }

  void set_path_model::revert_last (void)
  {
    clear ();

    beginInsertRows (QModelIndex (), 0, m_last_dirs.size () - 1);
    m_dirs = m_last_dirs;
    endInsertRows ();

    model_to_path ();
  }

  void set_path_model::add_dir (const QString& p)
  {
    m_last_dirs = m_dirs;

    beginInsertRows (QModelIndex (), m_dirs.size (), m_dirs.size ());

    QList<QString>::Iterator it = m_dirs.begin();

    m_dirs.insert (it, p);

    endInsertRows ();

    model_to_path ();
  }

  void set_path_model::rm_dir (const QModelIndexList& indices)
  {
    m_last_dirs = m_dirs;

    for (int i = indices.size () - 1; i >= 0; i--)
      {
        const QModelIndex& idx = indices.at (i);

        beginRemoveRows (idx, idx.row (), idx.row ());
        m_dirs.removeAt (idx.row ());
        endRemoveRows ();
      }

    model_to_path ();
  }

  void set_path_model::move_dir_up (const QModelIndexList& indices)
  {
    m_last_dirs = m_dirs;

    for (int i = 0; i < indices.size (); i++)
      {
        const QModelIndex& idx = indices.at (i);

        if (idx.row () == 0 )
          continue; //  already at top position

        beginMoveRows (idx, idx.row (), idx.row (),
                       this->index (idx.row () - 1), idx.row () - 1);

        m_dirs.move (idx.row (), idx.row () - 1);

        endMoveRows ();
      }

    model_to_path ();
  }

  void set_path_model::move_dir_down (const QModelIndexList& indices)
  {
    m_last_dirs = m_dirs;

    for (int i = indices.size () - 1; i >= 0; i--)
      {
        const QModelIndex& idx = indices.at (i);
        int bottom = m_dirs.size () - 1;

        if (idx.row () >= bottom)
          continue; //  already at bottom position

        beginMoveRows (idx, idx.row (), idx.row (),
                       this->index (idx.row () + 1), idx.row () + 1);

        m_dirs.move (idx.row (), idx.row () + 1);

        endMoveRows ();
      }

    model_to_path ();
  }

  void set_path_model::move_dir_top (const QModelIndexList& indices)
  {
    m_last_dirs = m_dirs;

    for (int i = 0; i < indices.size (); i++)
      {
        const QModelIndex& idx = indices.at (i);

        if (idx.row () == i)
          continue; //  already at target position

        beginMoveRows (idx, idx.row (), idx.row (), this->index (i), i);

        m_dirs.move (idx.row (), i);

        endMoveRows ();
      }

    model_to_path ();
  }

  void set_path_model::move_dir_bottom (const QModelIndexList& indices)
  {
    m_last_dirs = m_dirs;

    for (int i = 0; i < indices.size (); i++)
      {
        const QModelIndex& idx = indices.at (i);
        int target = m_dirs.size () - 1 - i;

        if (idx.row () == target)
          continue; //  already at target position

        beginMoveRows (idx, idx.row (), idx.row (),
                       this->index (target), target);

        m_dirs.move (idx.row (), target);

        endMoveRows ();
      }

    model_to_path ();
  }

  int set_path_model::rowCount (const QModelIndex&) const
  {
    return m_dirs.size ();
  }

  QVariant set_path_model::data (const QModelIndex& idx, int role) const
  {
    QVariant retval;
    if (idx.isValid ())
      {
        switch (role)
          {
          case Qt::DisplayRole:
            retval = QVariant (m_dirs[idx.row ()]);
            break;

          case Qt::DecorationRole:
            retval = QVariant (QIcon ());
            break;

          case Qt::SizeHintRole:
            retval = QVariant (QSize (10, 20));
            break;
          }
      }

    return retval;
  }

  void set_path_model::path_to_model (void)
  {
    emit interpreter_event
      ([=] (interpreter& interp)
       {
         // INTERPRETER THREAD

         load_path& lp = interp.get_load_path ();

         std::list<std::string> dir_list = lp.dir_list ();

         QStringList qs_dir_list;

         for (const auto& dir : dir_list)
           qs_dir_list << QString::fromStdString (dir);

         emit update_data_signal (qs_dir_list);
       });

       m_revertible = false;
  }

  void set_path_model::update_data (const QStringList& dirs)
  {
    m_dirs = dirs;

    m_dirs.removeAll (".");

    if (! m_revertible)
      {
        // first time update
        m_orig_dirs = m_dirs;
        m_last_dirs = m_dirs;

        m_revertible = true;
      }

    int numel = m_dirs.size ();

    emit dataChanged (QAbstractListModel::index (0, 0),
                      QAbstractListModel::index (numel-1, 0));
  }
}
